Dental articulator.



- 'No. 683,640. Patented (lot. I, mm.

H. DE w. cnoss.

DENTAL ARTIGU LATOR.

(Application filed Oct. 30, 1900.) (No Model.) 2 Sheets-Shed! WITNESSES:

No. 683,640. Patented Out. I, lam.

H. ma w. cnoss.

DENTAL ARTIGULATOR.

(Application filed Oct. 30, 1900.) (No Model.) 2 Sheets-Sheet 2.

WITNESSES:

MWZ

JMmd

- and useful Improvements'in Dental Articu 'cure the most perfect and natural articula- IJNITED STATES PATENT ()EEI'CE.

HAROLD DE W. oaoss, OF NASHUA, NEW HAMPSHIRE, Assieuor. TO THE S. S. WHITE DENTAL PENNSYLVANIA.

MANUFACTURING COMPANY, OF PHILADELPHIA,

DENTAL ARTICULATOR.'

sPEcIFIoATIoN forming part of Letters P atent No. 683,640, dated October 1, 190i.

Application filed October 30, 1900. Serial No. 84,890- (No model.)

To all whom it may concern:

Be it known that 1, HAROLD DE W. ORoss, a citizen of the United States, residing at Nashua, in the county of Hillsboro and State of New Hampshire, have invented certain new lators; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to articulators em ployed by dentists for obtaining the proper articulation and occlusion of artificial teeth mounted upon plates to be worn in the mouth.

Since the purpose of the articulator is to setion and occlusion of artificial teeth, it is important that the lower member or jaw of the articulator have the capacity of being moved similarly to the movements of the human mandible. A fairly close approximation of these movements has already been attained in a class of articulators heretofore constructed and known as anatomical or physiological articulators. The movements which may be imparted to these articulators are secured by constructing them in imitation of the human mandible. This construction, however, is objectionable, because of the extreme width of the articulators, which renders them bulky and difficult to handle.

The object of my invention is the production of an articulator having all the desirable and natural movements of the human mandible and which overcomes the objections found in other articulators of this type. This I accomplish by an improved connection, hereinafter fully described and claimed, between the articulator members, which connection, while affording the desired movements, involves a construction wholly different from that of the human jaws and enables me to. provide an articulator having a very narrow width, and hence convenient and easy to handle.

In the accompanyin g drawings I have illustrated dental articulators embodying the principle of my invention and which I prefer to designate the arthrodial articulator,

because of the peculiar life-like sliding joint or connection between the members.

In said drawings, Figure 1 is a viewiu side elevation of one form of my improved articulator. Fig. 2 is a plan or top view of the same: Fig. 3 is a plan or top view of the lower member thereof with the upper member and con necting parts omitted. Fig. 4 is a plan or top View of the connecting-plate between the articulator members detached. Fig. 5 is an inverted plan view of said connecting-plate, also detached. Fig. 6 is a vertical central sectional view through said connecting-plate and the guide-plate of the lower member of the articulator. Fig. 7 is a perspective view of a crown articulator constructed according to'my invention.

The lower member or jaw A of the articulator for holding the model of the lower denture is provided with a fixed or rigid guideplate B, extending rearwardly and in line with the longitudinal center of the articulator. In the present instance the guide-plate is formed bya continuation of the side arms A A, projecting rearwardly and upwardly from the lower member. The guide-plate has a flat upper surface, the plane of which is an angle of approximately thirty degrees (30) relatively to the plane of said lower member. The opposite sides or edges b b of the guideplate, as clearly shown in Fig. 3, are similarly curved, and the plate tapers or becomes narrower toward its rear extremity. It is also formed with an elongated slot B, extending centrally and longitudinally thereof.

A connecting-plate 0, having sliding connection with the guide-plate B, serves as the means for uniting the upper articulator member D to the lower member A. A thumbscrew E, passing loosely through the guideplate slot and screwing into the connectingplate, as plainly shown in Fig. 6, forms the connection between the two plates. The upper member D, to which a model of the upper denture is to be attached, is hinged or pivoted by way of its inner section D to the connecting-plate C by means of a pintle F passing through ears 0 O of the connectingplate and ears D D of the inner section D of the upper member D. Depending from the rear of the connecting-plate on opposite sides thereof are lugs c c, which assist in guiding and limiting the movements of the lower member A. Lugs b b may also be provided on the guide-plate B for further assisting in limiting the movements of the parts. An adjustable stop for securing the proper bite or distance apart of the articulator members is afiorded by means of a thumbscrew G, supported in an extension or bracket 0 of the connecting-plate.

The connection just described permits the lower member of the articulator to be moved backward and forward, upward and downward, and laterally in respect to the upper member, which is presumed to be held in a fixed position, although obviously the lower member may be held and the upper member moved, or both members maybe moved at the same time relatively to each other. For the purpose of description the upper member will be regarded as fixed and the lower member movable. Also the movement of the members about their hinged connection will not be considered herein. The movements above alluded to and now more fully to be described are accomplished by the guideplate B sliding upon the connecting-plate O, and consequently all the movements are in an inclined plane relatively to the members. The lower member may be moved backward and forward without lateral motion the distance permitted by the guide-plate slot. This movement owing to the inclination of the guide-plate is not a simple back-and-forth motion, but is also an up-and-down motion. This will be apparent from Fig. 1, the full lines thereof indicating the lower member in a central posit-ion, dotted lines 00 indicating said member in its extreme upper and backward position, and dotted lines y indicating said member in its extreme lower and forward position. The lower member may also be moved laterally to opposite sides of the center of the articulator about the thumbscrew E as a center, the movement to right and left being limited by the sides of the guide-plate coming in contact with the lugs or stops 0 c on the connecting-plate. As the pivot about which the lower member turns is a movable one and as the guide-plate tapers toward its rear extremity, the range of lateral movement permitted said member varies according to its longitudinal position on the connecting-plate. Thus when thelower member is in its'extreme upper or backward position it is permitted little or no lateral movement; but when in its extreme lower and forward position it is susceptible of its maximum lateral movement. The line of lateral movement of the lower member is not in a plane parallel with the plane of the upper member, but is somewhat curved, owing to the obliquity of the axis about which said lower member turns.

A very important feature of the movements of which the lower member is capable is that made possibleby the peculiar shape of the guide-plate and its elongated slot,- thumbscrew E, and the lugs c c of the connectingplate. These elements not only limit the lateral movement of the lower member, as before pointed out, but they also cause the move ments of this member to more closely simulate the movements of the human mandible-that is to say, when the lower member is moved laterally it is not compelled to turn about a fixed pivotal center; but said member may be so moved laterally as to cause its center to move in a curved line,t-his being caused by one of the curved sides of the guide-plate bearing against the adjacent lug of the connecting-plate. In other words, the lower member may be moved laterally in such manner that it is caused to move outwardly and downwardly or upwardly and rearwardly,the inclined guide-plate moving laterally and backward or forward on the connecting-plate, and the elongatedslot moving endwise about the thumb-screw. Whenever desired,the lower member may, by means of the thumb-screw E, be locked in any position to which it may be adjusted.

The motions of my improved articulator very closely and correctly reproduce the motions of the human mandiblegvhereby models of natural teeth mounted upon the articulator members can be made to articulate precisely as the original teeth do. The inclined plane formed by the guide-plate A,- having an inclination of approximately thirty degrees (30) relative to the lower member and which to a considerable degree determines the lifelike motions of said member, corresponds to the plane of inclination of the average human mandible. This plate may be slightlycurved longitudinally; but this I do not deem necessary. Each side or edge I) of the guide-plate, which sides, together with the lugs of the connecting-plate and the elongated slot and thumb-screw,complete the organization which determines the before-mentioned life-like motions, is curved in the arc of a circle, the center of which is a point correspondingapproximately to the condyle farthest from it. This exact curvature is not essential, because during mastication the oscillations of the mandible are not produced by a simple pivoting of either condyle, but by an intermediate position, with one condyle thrust forward a little in advance of the other, but both being forward of the position of rest.

By my improved construction I not only reproduce the movements of the human mandible, but overcome certain objections found in articulators of a like type. Instead of the usual objectionable width, which renders this class of articulators exceedingly bulky and awkward to handle Iam enabled to construct an articulator which is very narrow and light, and hence easily held in the hand when in use. I am also enabled to dispense with the spring or springs employed in articulators of eeaeao this class, and since the hands are not under tension in moving the lower member of the articulator the same may be adjusted more easily and conveniently and a more exact and delicate occlusion of the teeth secured. The improved articulator also possesses other advantages,which will be understood and appreciated by dentists.

I11 Fig. 7 I have showna crown-articulator embodying the principle of my invention. It will be unnecessary to describe the construction and operation of this articulator in detail, as it is in most respects similar to the one just described, with the exception that it is smaller and simpler and adapted for the special purpose for which crown-articulators are intended. It might be well to say, however, that the guide-plate 11, connected to the lower member I, is provided with a fixed post or lug H, adapted to move in aslotj of the connecting-plate J, to which the upper member K of the articulator is hinged. The lug H and slotj, together with the slot h of the guide-plate, thumb -screw L and lugs j j, determine the movements of the parts, as before described.

The principle of my invention may obviously be embodied in articulators differing very materially in construction from the articulators herein shown and described. My invention, therefore, is not limited to these particular articulators, but includes all articulatorsinvolvin g the principle of construction defined in the following claims.

I claim as my invention- 1. In a dental articulator, the combination of the upper and lower members and the connection between the same, said connection being in alinement with the longitudinal center of the articulator and consisting of two plain surfaces capable of sliding and turning relatively to each other, said movements of said two plain surfaces being in a fixed plane inclined obliquely to the plane of said lower member, substantially as and for the purpose described.

2. In a dental articulator, the combination of the upper and lower members, a centrallydisposed rigid extension or guide-plate on one of said members inclined obliquely to the plane of said member, and the sliding connection between the other member and said inclined guide-plate, substantially as and for the purpose described.

3. In a dental articulator, the combination of the two members, a slotted guide-plate on one of said members permanently inclined obliquely to the plane of said member, a connecting-plate having pivotal and sliding connection with said guide-plate, the other mcm-- ber of the articulator having hinged connection with said connecting-plate, and means for guiding and limiting the movements of said guide-plate and said connecting-plate in respect to each other, substantially as and for the purpose described;

4. In a dental articulator, the combination of the two members, a slotted guide-plate on one of said members permanently inclined obliquely to the plane of said member, a connecting-plate having pivotal and sliding connection with said guide-plate, the other member of the articulator having hinged connection with said connecting-plate,and means for guiding and limiting the movements of the guide-plate and connecting-plate in respect to each other and for locking said plates together in any desired position, substantially as and for the purpose described.

5. In a dental articulator, the combination of the lower member, the rearwardly-extend= ing guide-plate thereof centrally disposed in relation to the longitudinal center of the articulator and inclined in a fixed oblique angle relatively to said lower member, the said guide-plate tapering rearwardly and having curved sides or edges and a central longitu dinal slot, a connecting-plate fitted to slide upon said guide-plate and provided with lugs, means for connecting said connecting-plate to said guide-plate, and the upper member having hinged connection with said connecting-plate, substantially as and for the purpose described.

6. In a dental articulator, the combination of the upper and lower members, the single compound sliding and turningrconnection between said members, and a single device for locking said members in any position to which they may be adjusted, substantially as and for the purpose described.

7. In a dental articulator, the combination of the upper and lower members, the single compound sliding and turningconnection between said members, the movements afforded by this connection being in a fixed plane inclined relatively to the plane of said members, and a single device for locking said members in any position to which they may be adj usted, substantially as and for the purpose described.

In testimony whereof I affix my signature in presence of two witnesses.

HAROLD DE IV. CROSS.

Witnesses:

E. B. GOULD, E. E. STAPLES. 

